The average of five numbers is 27

The average of five numbers is 27. If one number is excluded, the average becomes 25. The excluded number is?

This problem repeats another one in the library (at most with different numbers), so it's left out of browsing.

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #26478